Summary

Cisco IOS® devices that are configured for
Cisco Unified Communications Manager Express (CME) and the Extension Mobility
feature are vulnerable to a buffer overflow vulnerability. Successful
exploitation of this vulnerability may result in the execution of arbitrary
code or a Denial of Service (DoS) condition on an affected device.

Note: The September 23, 2009, Cisco IOS Security Advisory bundled
publication includes eleven Security Advisories. Ten of the advisories address
vulnerabilities in Cisco IOS Software, and one advisory addresses a
vulnerability in Cisco Unified Communications Manager. Each advisory lists the
releases that correct the vulnerability or vulnerabilities detailed in the
advisory.

Affected Products

Cisco IOS devices, including Cisco Unified Communications 500 Series,
that are configured for Cisco Unified CME and the Extension Mobility feature
are affected.

Vulnerable Products

A Cisco IOS device that is configured for Cisco Unified CME and
Extension Mobility contains the following output when the show
running-config command is issued:

ephone [Ethernet phone tag]
...
logout-profile [logout-profile tag]

To determine the Cisco IOS Software release that is running on a Cisco
product, administrators can log in to the device and issue the show
version command to display the system banner. The system banner
confirms that the device is running Cisco IOS Software by displaying text
similar to "Cisco Internetwork Operating System Software" or "Cisco IOS
Software." The image name is displayed in parentheses, followed by "Version"
and the Cisco IOS Software release name. Other Cisco devices do not have the
show version command or may provide different output.

The following example identifies a Cisco product that is
running Cisco IOS Software Release 12.3(26) with an installed image name of
C2500-IS-L:

Products Confirmed Not Vulnerable

Cisco IOS devices that are configured for Survivable Remote Site
Telephony (SRST) Mode are not affected.

Cisco IOS XR is not affected.

Cisco IOS XE is not affected.

Cisco Unified Communications Manager is not
affected.

Cisco Unified CME is not affected unless configured to use
the Extension Mobility feature.

No other Cisco products are currently known to be affected
by these vulnerabilities.

Details

Cisco Unified CME is the call processing component of an enhanced IP
telephony solution that is integrated into Cisco IOS.

The Extension Mobility feature in Cisco Unified CME
provides the benefit of phone mobility for end users. A user login service
allows phone users to temporarily access a physical phone other than their own
phone and utilize their personal settings, such as directory number, speed-dial
lists, and services, that is assigned to their own desk phone. The phone user
can make and receive calls on that phone using the same personal directory
number as is on their own desk phone. More information on Extension Mobility
feature is available at the following URL:

A vulnerability in the login section of the Extension
Mobility feature may allow an unauthenticated attacker to execute arbitrary
code or cause a Denial of Service (DoS) condition. Such packets can only come
from registered phone IP addresses in the form of HTTP requests. If the
auto-registration feature is enabled, an attacker can register its IP address
and subsequently send a crafted payload to exploit this vulnerability. The
auto-registration feature is enabled by default. More information on
auto-registration can be found at the following link:

This vulnerability is addressed by the Cisco Bug ID
CSCsq58779
(registered customers only)
and has been assigned
Common Vulnerabilities and Exposures (CVE) ID CVE-2009-2865.

Workarounds

There are no workarounds to mitigate this vulnerability, other than
disabling Extension Mobility. However, auto-registration can be disabled to
make exploitation more difficult. Auto-registration can be disabled by the
following command:

telephony-service
no auto-reg-ephone

Before disabling auto-registration, all phone MAC addresses need to be
explicitly defined on the Cisco Unified CME. Otherwise phones will not be able
to register. More information on auto-registration can be found at the
following link:

Fixed Software

When considering software upgrades, also consult
http://www.cisco.com/go/psirt
and any subsequent advisories to determine exposure and a complete upgrade
solution.

In all cases, customers should exercise caution to be
certain the devices to be upgraded contain sufficient memory and that current
hardware and software configurations will continue to be supported properly by
the new release. If the information is not clear, contact the Cisco Technical
Assistance Center (TAC) or your contracted maintenance provider for assistance.

Each row of the Cisco IOS software table (below) names a
Cisco IOS release train. If a given release train is vulnerable, then the
earliest possible releases that contain the fix (along with the anticipated
date of availability for each, if applicable) are listed in the "First Fixed
Release" column of the table. The "Recommended Release" column indicates the
releases which have fixes for all the published vulnerabilities at the time of
this Advisory. A device running a release in the given train that is earlier
than the release in a specific column (less than the First Fixed Release) is
known to be vulnerable. Cisco recommends upgrading to a release equal to or
later than the release in the "Recommended Releases" column of the table.

Major Release

Availability of Repaired
Releases

Affected 12.0-Based Releases

First Fixed Release

Recommended Release

There are no affected 12.0 based releases.

Affected 12.1-Based Releases

First Fixed Release

Recommended Release

There are no affected 12.1 based releases.

Affected 12.2-Based Releases

First Fixed Release

Recommended Release

There are no affected 12.2 based releases.

Affected 12.3-Based Releases

First Fixed Release

Recommended Release

There are no affected 12.3 based releases.

Affected 12.4-Based Releases

First Fixed Release

Recommended Release

12.4

Not Vulnerable

12.4GC

Not Vulnerable

12.4JA

Not Vulnerable

12.4JDA

Not Vulnerable

12.4JDC

Not Vulnerable

12.4JDD

Not Vulnerable

12.4JK

Not Vulnerable

12.4JL

Not Vulnerable

12.4JMA

Not Vulnerable

12.4JMB

Not Vulnerable

12.4JX

Not Vulnerable

12.4MD

Not Vulnerable

12.4MDA

Not Vulnerable

12.4MR

Not Vulnerable

12.4SW

Not Vulnerable

12.4T

Not Vulnerable

12.4XA

Not Vulnerable

12.4XB

Not Vulnerable

12.4XC

Not Vulnerable

12.4XD

Not Vulnerable

12.4XE

Not Vulnerable

12.4XF

Not Vulnerable

12.4XG

Not Vulnerable

12.4XJ

Not Vulnerable

12.4XK

Not Vulnerable

12.4XL

Not Vulnerable

12.4XM

Not Vulnerable

12.4XN

Not Vulnerable

12.4XP

Not Vulnerable

12.4XQ

Not Vulnerable

12.4XR

Not Vulnerable

12.4XT

Not Vulnerable

12.4XV

Not Vulnerable

12.4XW

12.4(11)XW8

12.4(20)T4

12.4(22)T3

12.4(24)T2; Available on 23-OCT-2009

12.4XY

12.4(15)XY4

12.4(20)T4

12.4(22)T3

12.4(24)T2; Available on 23-OCT-2009

12.4XZ

12.4(15)XZ1

12.4(20)T4

12.4(22)T3

12.4(24)T2; Available on 23-OCT-2009

12.4YA

12.4(20)YA1

12.4(20)T4

12.4(22)T3

12.4(24)T2; Available on 23-OCT-2009

12.4YB

Not Vulnerable

12.4YD

Not Vulnerable

12.4YE

Not Vulnerable

Exploitation and Public Announcements

The Cisco PSIRT is not aware of any public announcements or malicious
use of the vulnerability described in this advisory.

This vulnerability was found internally.

Cisco Security Vulnerability Policy

To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.

URL

Revision History

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Cisco Security Vulnerability Policy

To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.